van Kimmenade Roland R J, Januzzi James L, Bakker Jaap A, Houben Alphonse J, Rennenberg Roger, Kroon Abraham A, Crijns Harry J G M, van Dieijen-Visser Marja P, de Leeuw Peter W, Pinto Yigal M
Department of Cardiology, University Hospital Maastricht, the Netherlands.
J Am Coll Cardiol. 2009 Mar 10;53(10):884-90. doi: 10.1016/j.jacc.2008.11.032.
This study sought to compare the renal clearance mechanisms of B-type natriuretic peptide (BNP) and amino terminal pro-B-type natriuretic peptide (NT-proBNP).
The small molecular weight proteins (SMWPs) BNP and NT-proBNP both inversely correlate with glomerular filtration rate (GFR). Whether this association is causal or confounding is unknown and has been the basis of widespread speculation.
We combined measurements of BNP and NT-proBNP concentrations in the renal arteries and veins of 165 subjects undergoing renal arteriography with invasive renal plasma flow (RPF) measurements and echocardiography. Fractional extraction (FE) of BNP and NT-proBNP was computed.
The BNP and NT-proBNP concentrations correlated similarly to GFR (r = -0.35 and r = -0.30, respectively; p < 0.001 for both) but the NT-proBNP/BNP serum ratio was negatively associated with GFR (r = -0.21, p = 0.008). Median FE(BNP) was 0.21 (interquartile range [IQR] 0.16 to 0.22) for left and 0.22 (IQR 0.17 to 0.29) for right kidneys. Median FE(NT-proBNP) was 0.16 (IQR 0.09 to 20) for left and 0.18 (IQR 0.12 to 0.22) for right kidneys. The FE(BNP) correlated with GFR (left: r = 0.26, p = 0.008; right: r = 0.21, p = 0.03) as did FE(NT-proBNP) (left: r = 0.25, p = 0.005; right: r = 0.20, p = 0.02). Although FE(BNP) and FE(NT-proBNP) correlated strongly with each other (left: r = 0.66; right: r = 0.60; p < 0.001 for both), left and right FE(NT-proBNP/BNP) ratios were not influenced by GFR (r = 0.10, p = 0.30 and r = 0.08, p = 0.43, respectively). Multivariate analyses confirmed that FE was not independently associated with BNP or NT-proBNP concentrations.
Contrary to widespread belief (but in line with the renal physiology of SMWP), BNP and NT-proBNP are equally dependent on renal function for their clearance.
本研究旨在比较B型利钠肽（BNP）和氨基末端前B型利钠肽（NT-proBNP）的肾脏清除机制。
小分子重量蛋白（SMWPs）BNP和NT-proBNP均与肾小球滤过率（GFR）呈负相关。这种关联是因果关系还是混杂因素尚不清楚，一直是广泛猜测的基础。
我们将165例接受肾动脉造影的受试者肾动脉和静脉中的BNP和NT-proBNP浓度测量结果与有创肾血浆流量（RPF）测量结果及超声心动图相结合。计算BNP和NT-proBNP的分数提取率（FE）。
BNP和NT-proBNP浓度与GFR的相关性相似（分别为r = -0.35和r = -0.30；两者p均<0.001），但NT-proBNP/BNP血清比值与GFR呈负相关（r = -0.21，p = 0.008）。左肾FE（BNP）中位数为0.21（四分位间距[IQR]0.16至0.22），右肾为0.22（IQR 0.17至0.29）。左肾FE（NT-proBNP）中位数为0.16（IQR 0.09至0.20），右肾为0.18（IQR 0.12至0.22）。FE（BNP）与GFR相关（左：r = 0.26，p = 0.008；右：r = 0.21，p = 0.03），FE（NT-proBNP）也是如此（左：r = 0.25，p = 0.005；右：r = 0.20，p = 0.02）。虽然FE（BNP）和FE（NT-proBNP）彼此高度相关（左：r = 0.66；右：r = 0.60；两者p均<0.001），但左、右FE（NT-proBNP/BNP）比值不受GFR影响（分别为r = 0.10，p = 0.30和r = 0.08，p = 0.43）。多变量分析证实，FE与BNP或NT-proBNP浓度无独立相关性。
与普遍看法相反（但符合SMWP的肾脏生理学），BNP和NT-proBNP在清除方面对肾功能的依赖性相同。
